Buying guide for best mold test kits
Written by Samantha Bookman
Updated April 2022
Scientifically, mold has its place in nature — shout out to blue cheese — but in the home, many molds can cause allergies, exacerbate asthma symptoms, and have even been implicated in chronic health conditions. Mold is a health hazard that can’t always be seen or smelled, so a mold test kit is an inexpensive way to make sure your home is free of it.
Using a kit is not difficult: Users collect a sample of air particles, dust particles from a furniture surface, or a swab of an area of suspected mold growth. The accuracy of a mold test is important — and so is choosing the right test kit for your situation as each one has its pros and cons.
Read on to learn which mold test kit is the right one for your situation. If you’re ready to buy, consider one of our recommended products.
Buildings with a very musty smell or poor air circulation should be tested for mold before moving in.
You suspect a mold problem. Now what?
Mold tests need to be performed in multiple locations throughout the home, not just in the area where mold is suspected. Mold spores can be carried by air currents into other rooms and mold tends to grow in hard-to-reach spots, like wall spaces and air vents. That means either buying multiple mold test kits or choosing a mold test kit with several tests included.
While some mold test kits have chemical strips that indicate the presence of mold and even the types of mold, these strips are not as accurate as a lab analysis. Sending samples to a lab costs extra in most cases, and you’ll need to wait for the results, which can take weeks.
Regardless of the lab results, if mold is present in your home, it’s strongly recommended that you have an air-quality specialist come in to do more in-depth testing of the entire home and help pinpoint the source of the mold. All homes have some mold spores in them, but a professional can determine if the problem is bad enough that action is needed.
Homeowners should review their insurance policy to learn whether advanced testing and repairs are covered. Renters should contact their management company or landlord immediately after a positive result from a home mold test kit so that advanced testing and remediation efforts can start as soon as possible.
Did you know?
Water leaks are the most common sources of mold growth. Leaks in the foundation, in the roof, or from damaged plumbing can all cause problems and should be fixed as soon as possible.
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Test kits
A variety of mold test kits are available, but the majority are based on collecting samples from a room’s air or directly collecting a sample from a suspected area of mold growth, like a water-damaged ceiling. Here are some of the different types of mold test kits:
Air check: Similar to the gear used by professionals, this is the most expensive and accurate mold test kit. Samples are taken in specific areas and fixed to test cassettes, which are analyzed at a lab to identify the exact type of mold spore, pollen, or dust.
Instant: This test kit uses chemical test strips that indicate the presence of mold spores. More advanced testing is often needed to determine what type of mold is present.
- Settling plate: This kit uses a petri dish or a film with which the user collects a sample of the air particles in a room. The dish or film is opened up and left near the suspected area of mold for several hours so that air particles can settle in the gummy medium at the bottom. Then, the dish or film is covered and incubated for about a week; if mold grows, the user can have it analyzed further.
Types of tests
Mold test kits often include different types of tests. Each test type can be purchased separately, and it’s best to use a couple of different test methods — such as tape strip and swab — to get a better range of results. Here are some of the tests you may find:
Tape strips: Best for dry surfaces, a tape strip is placed so that the sticky side is on the surface you want to test. Pull up the tape, place in a sample container or bag, and send it off for analysis.
Swabs (aka visual sample): Good for damp surfaces or visible mold spots, this test features a swab that is rubbed over the suspected surface to collect the test sample. Like a tape strip, a swab is placed in a container and sent to a lab for analysis.
Chemical strips: For home users, these strips can determine the presence of proteins common in molds in just a few minutes. They aren’t very precise, so a follow-up lab analysis is a must.
- Collection film or petri dish: Collecting air particle samples is fairly accurate when using this method, known as settling plate collection. It takes a few days for any molds to incubate in the sticky medium that coats the film or the bottom of the petri dish, but users can visually identify what’s in their air.
Mold test kit prices
Inexpensive: The lowest-priced mold test kits start for as little as $9, but keep in mind that most of them require a lab analysis for an additional fee of $40 or more.
Mid-range: Mold test kits that include the lab analysis fee are available for around $30 to $60.
Expensive: At the high end of the price spectrum, you’ll find mold test kits that typically include three or more sample collectors as well as the lab analysis for $75 to $95.
Tips
Use more than one test in different parts of the building to get a more accurate picture of possible mold.
Place one sample collector or use a tape strip or swab as close to the suspected source of mold as you can.
Mold tests should also be conducted in adjoining rooms and on other floors to determine if the mold is widespread.
If a test is positive for mold, follow up with a lab analysis and additional testing from a professional air-quality service to confirm the results.
When performing a swab test, be sure to coat the swab thoroughly to get a good sample.
Don’t use a mold test kit that is already open or damaged. If it has an expiration date, don’t use the test kit after that date.
- When testing for mold in an HVAC system, run the system for about 10 minutes before placing the sample collector to clear out accumulated particles and get a more accurate reading.
Heating and air conditioning ducts can harbor molds and allergens, so a mold test should be done near a vent or register — ideally the vent farthest from the HVAC system.
FAQ
Q. I used a viable plate sample collector to test for mold and several types of mold grew in the petri dish. Should I start treating my home for mold right away?
A. A home mold test kit should be seen as just the first step in detecting possible mold. Always follow up with a professional contractor who specializes in testing for and locating sources of mold contamination. All buildings contain mold, mildew, pollen, and dust; however, if mold is getting a strong foothold due to a problem such as a roof leak, more thorough testing will help determine that source, so you can fix the problem and restore a balance.
Q. How do chemical test strips work?
A. Once a sample is collected — either by using a swab on a damp surface or a plate-type collector, such as a petri dish or film —the sample is mixed with a neutral liquid. The chemical test strip, which has a reagent in it, is then dipped in the mixture. The color of the test strip changes depending on what is present in the sample. A chemical strip test kit will include a color key, so you can interpret the results.
Q. How do I know if my home is free of mold once repairs have been made?
A. After fixing the problem that caused the mold, you can use a mold test kit to test for the presence of mold. Again, always follow up with a professional if the test kit’s results are positive.
